rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=26fc/1/0x4000000000000000 softirq=100072/100073 fqs=2
rcu: 	(detected by 0, t=10502 jiffies, g=136337, q=149 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 21531 Comm: syz.3.3884 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:__lock_is_held kernel/locking/lockdep.c:5492 [inline]
RIP: 0010:lock_is_held_type+0xae/0x190 kernel/locking/lockdep.c:5825
Code: 00 00 00 7e 4b 44 89 fd 49 89 df 49 81 c7 e0 0a 00 00 45 31 e4 49 83 fc 31 73 24 4c 89 ff 4c 89 f6 e8 26 02 00 00 85 c0 75 2a <49> ff c4 48 63 83 d8 0a 00 00 49 83 c7 28 49 39 c4 7c d8 eb 11 48
RSP: 0000:ffffc900001efed8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff888023b51e00 RCX: 0000000000000000
RDX: ffff888023b51e00 RSI: ffff8880b8f2b758 RDI: ffff888023b528e0
RBP: 00000000ffffffff R08: ffff88807800e357 R09: 0000000000000000
R10: ffff88807800e340 R11: ffffed100f001c6b R12: 0000000000000000
R13: 0000000000000046 R14: ffff8880b8f2b758 R15: ffff888023b528e0
FS:  00007feee858a6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffe70 CR3: 000000007e5da000 CR4: 00000000003506e0
Call Trace:
 <IRQ>
 lock_is_held include/linux/lockdep.h:288 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1720 [inline]
 __hrtimer_run_queues+0x29e/0xc10 kernel/time/hrtimer.c:1818
 hrtimer_interrupt+0x39d/0x980 kernel/time/hrtimer.c:1880
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
 __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0x51/0xc0 arch/x86/kernel/apic/apic.c:1088
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:inet_ehashfn+0x0/0x1e0 net/ipv4/inet_hashtables.c:34
Code: 4c 89 ff 4c 89 f6 48 89 da e8 ec 12 2d fb 48 89 c3 89 d8 5b 41 5c 41 5e 41 5f 5d c3 e8 99 e7 82 f8 0f 0b eb ec cc cc cc cc cc <f3> 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48
RSP: 0000:ffffc900001f0278 EFLAGS: 00000246
RAX: 00000000a300800a RBX: 000000000000b960 RCX: 00000000a300800a
RDX: 000000000000b960 RSI: 000000007000800a RDI: ffffffff976b6440
RBP: ffffc900001f03c0 R08: 0000000000004e75 R09: 000000000000b960
R10: 0000000000000011 R11: 0000000000000100 R12: 000000007000800a
R13: 00000000a300800a R14: ffffffff976b6440 R15: ffffffff976d6e00
 __inet_lookup_established+0xbd/0x830 net/ipv4/inet_hashtables.c:510
 tcp_v4_early_demux+0x453/0x9e0 net/ipv4/tcp_ipv4.c:1803
 ip_rcv_finish_core+0x10b2/0x1bd0 net/ipv4/ip_input.c:341
 ip_list_rcv_finish net/ipv4/ip_input.c:613 [inline]
 ip_sublist_rcv+0x3e7/0xd60 net/ipv4/ip_input.c:639
 ip_list_rcv+0x3ed/0x440 net/ipv4/ip_input.c:674
 __netif_receive_skb_list_ptype net/core/dev.c:5689 [inline]
 __netif_receive_skb_list_core+0x582/0x770 net/core/dev.c:5737
 __netif_receive_skb_list net/core/dev.c:5789 [inline]
 netif_receive_skb_list_internal+0x943/0xca0 net/core/dev.c:5880
 gro_normal_list include/net/gro.h:451 [inline]
 napi_complete_done+0x329/0x820 net/core/dev.c:6220
 virtqueue_napi_complete drivers/net/virtio_net.c:450 [inline]
 virtnet_poll+0xaa0/0x11e0 drivers/net/virtio_net.c:2236
 __napi_poll+0xbb/0x460 net/core/dev.c:6650
 napi_poll net/core/dev.c:6717 [inline]
 net_rx_action+0x65f/0xcc0 net/core/dev.c:6853
 handle_softirqs+0x27d/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202
Code: 00 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 4a 39 d3 f6 48 89 df e8 f2 0c d4 f6 e8 bd 07 f8 f6 fb bf 01 00 00 00 <e8> 12 1d c7 f6 65 8b 05 e3 6b 6e 75 85 c0 74 02 5b c3 e8 b0 50 6b
RSP: 0000:ffffc9000be86eb0 EFLAGS: 00000282
RAX: a3c0946b5af05a00 RBX: ffff888022a468a0 RCX: a3c0946b5af05a00
RDX: dffffc0000000000 RSI: ffffffff8acacb60 RDI: 0000000000000001
RBP: ffffc9000be87020 R08: ffffffff911e75af R09: 1ffffffff223ceb5
R10: dffffc0000000000 R11: fffffbfff223ceb6 R12: ffffc9000be86f60
R13: 00000003fffffffc R14: 0000000000000cc0 R15: dffffc0000000000
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 shmem_add_to_page_cache+0xa36/0x1b80 mm/shmem.c:816
 shmem_get_folio_gfp+0x1037/0x2b40 mm/shmem.c:2071
 shmem_get_folio mm/shmem.c:2164 [inline]
 shmem_write_begin+0xf2/0x430 mm/shmem.c:2706
 generic_perform_write+0x2fe/0x5c0 mm/filemap.c:4036
 shmem_file_write_iter+0xfb/0x120 mm/shmem.c:2883
 __kernel_write_iter+0x29f/0x6d0 fs/read_write.c:517
 dump_emit_page fs/coredump.c:957 [inline]
 dump_user_range+0x418/0x840 fs/coredump.c:984
 elf_core_dump+0x320e/0x37c0 fs/binfmt_elf.c:2184
 do_coredump+0x1791/0x24a0 fs/coredump.c:833
 get_signal+0x10da/0x1390 kernel/signal.c:2889
 arch_do_signal_or_restart+0xc2/0x7b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 irqentry_exit_to_user_mode+0x9/0x30 kernel/entry/common.c:315
 exc_page_fault+0x8c/0x100 arch/x86/mm/fault.c:1519
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7feee779de61
Code: 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 48 3d 01 f0 ff ff 73 01 <c3> 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007feee7a25fa0 RCX: 00007feee779de59
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007feee7833e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007feee7a26038 R14: 00007feee7a25fa0 R15: 00007fff15fafd88
 </TASK>
rcu: rcu_preempt kthread starved for 10498 jiffies! g136337 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:27096 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x30d/0x1590 kernel/rcu/tree.c:1667
 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 21547 Comm: syz.3.3888 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline]
RIP: 0010:smp_call_function_many_cond+0xd85/0x1190 kernel/smp.c:855
Code: 45 8b 34 24 44 89 f6 83 e6 01 31 ff e8 34 f1 0a 00 41 83 e6 01 49 be 00 00 00 00 00 fc ff df 75 07 e8 6f ed 0a 00 eb 38 f3 90 <42> 0f b6 04 33 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 53 ed
RSP: 0018:ffffc9000461fa20 EFLAGS: 00000246
RAX: ffffffff817bf7fd RBX: 1ffff110171e82bd RCX: 0000000000080000
RDX: ffffc9000d42b000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000461fba0 R08: ffffffff911e7507 R09: 1ffffffff223cea0
R10: dffffc0000000000 R11: fffffbfff223cea1 R12: ffff8880b8f415e8
R13: ffff8880b8e3d3c0 R14: dffffc0000000000 R15: 0000000000000001
FS:  00007feee858a6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000080 CR3: 000000006c420000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1022
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:2222 [inline]
 text_poke_bp_batch+0x31e/0x980 arch/x86/kernel/alternative.c:2432
 text_poke_flush arch/x86/kernel/alternative.c:2623 [inline]
 text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2630
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_slow_inc_cpuslocked+0x80/0xe0 kernel/jump_label.c:165
 static_key_slow_inc+0x1a/0x30 kernel/jump_label.c:188
 bpf_enable_runtime_stats kernel/bpf/syscall.c:5322 [inline]
 bpf_enable_stats+0x101/0x140 kernel/bpf/syscall.c:5341
 __sys_bpf+0x63f/0x890 kernel/bpf/syscall.c:5560
 __do_sys_bpf kernel/bpf/syscall.c:5581 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5579 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5579
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7feee779de59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007feee858a028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007feee7a25fa0 RCX: 00007feee779de59
RDX: 0000000000000004 RSI: 0000200000000040 RDI: 0000000000000020
RBP: 00007feee7833e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007feee7a26038 R14: 00007feee7a25fa0 R15: 00007fff15fafd88
 </TASK>